The long-term objective of our project is to design, build, and market an ophthalmic instrument that simultaneously measures corneal topography, corneal aberrations, and whole-eye optical aberrations of the human eye using wavefront sensing technology. From these measurements our instrument will provide a complete description of the refractive properties of the anterior cornea, the whole eye, and (by inference) the crystalline lens. This optical description will include not only the routine refractive errors of myopia, hyperopia, and astigmatism normally measured by present day optometers and corneal topographers, but will also determine the irregular, higher-order optical aberrations that limit the quality of vision. This project is a joint venture of Wavefront Sciences, Inc. and Quarryment Optical, Inc. Our new, multipurpose instrument will be built around core technology of the Complete Ophthalmic Analysis System (COAS), a clinical whole-eye aberrometer currently marketed by Wavefront Sciences, Inc. In year I of this Phase II project we propose to add new functionallity to COAS for simultaneously measuring corneal topograhphy and corneal aberrometry. Quarrymen Optical, Inc. demonstrated feasibilty of such a multi-purpose instrument in Phase-I by building and validataing a prototype corneal topographer/aberrometer using core technology of a Shack-Hartmann wavefront sensor developed with previous STTR support. In year 2 we will experimentally validate and clinically evaluate our prototype instrument using clinically normal and abnormal human eyes. Our combined instrument will help provide wavefront-guided prescriptions for aberration corrections using inter-ocular lenses, corneal refractive surgery, or contact lenses. The long-term benefits will be improved patient care through improved diagnosis and treatment of optical defects of eyes.